Last 7 days
Bookmark and Share    
Full Text
See detailHeavy methane to explain the unexplained recent methane growth ?
Bader, Whitney ULiege; Strong, Kim; Walker, Kaley

Poster (2016, July)

Methane (CH4) is the second most important greenhouse gas emitted by human activities in the Earth’s atmosphere. Although it is roughly 200 times less abundant than carbon dioxide, it is a 28 times more ... [more ▼]

Methane (CH4) is the second most important greenhouse gas emitted by human activities in the Earth’s atmosphere. Although it is roughly 200 times less abundant than carbon dioxide, it is a 28 times more potent greenhouse gas. Approximately one fifth of the changes in the Earth’s balance energy caused by human-linked greenhouse gases since the beginning of industrialization (~1750) is due to methane. Methane is emitted by both natural sources and human activities. Indeed, methane can be emitted to the atmosphere through coal mining, oil and gas exploitation, rice cultures, domestic ruminant animals, biomass burning, waste management, wetlands, termites, methane hydrates and ocean. In the atmosphere, methane is mainly destroyed by the radical hydroxyl, also called the detergent of the atmosphere, and therefore plays a major role on the oxidizing capacity of the atmosphere. Since the beginning of the industrialization, atmospheric methane concentrations have increased by 260% to reach 1824 pbb in 2013. From the 1980s until the beginning of the 1990s, atmospheric methane was significantly on the rise, then stabilized during 1999-2006 to rise again afterwards. To this day, the source or sink responsible of this latter increase remains unexplained. Through each emission process, heavy molecules of methane (with one additional neutron either on a carbon or on one hydrogen atom) are emitted along methane (12CH4). The main heavy molecules of methane, called isotopologues (13CH4 and CH3D), are respectively ~110 and ~60 000 times less abundant than methane. Despite their small abundances, they give crucial information on the concentration of methane in the atmosphere and its evolution. Indeed, both isotopologues are emitted with specific emission ratio depending on the emission sources. Determining isotopic ratio of atmospheric methane is therefore a unique tracer of its budget. While the non-monotonous trend of methane is subject of an extensive number of studies, to our knowledge, no study of the isotopic ratio of methane derived from ground-based solar observations has been published to date. Measurements of heavy methane from Fourier Transform InfraRed spectra recorded with state of the art spectrometers installed at Eureka [Arctic, Canada] and Toronto [Ontario, Canada] along with analysis of observations collected by a portable instrument [Portable Atmospheric Research Interferometric Spectrometer for the Infrared, PARIS-IR], installed at Eureka will help fill this gap. Indeed, the produced time series, compared with the corresponding satellite observations (ACE-FTS) products will ease data interpretation and contribute to a global view of the question of isotopologues. [less ▲]

Detailed reference viewed: 86 (5 ULiège)
Peer Reviewed
See detailA Frasnian palynological assemblage from the NE Iberian Chain
Rial, Gonzalo; Cascales-Miñana, Borja ULiege; Gerrienne, Philippe ULiege et al

Poster (2016, July)

Detailed reference viewed: 22 (2 ULiège)
Peer Reviewed
See detailPlant-insect interactions from the Late Oligocene Ebro Basin (Estadilla, Huesca, Spain): A preliminary report
Moreno-Domínguez, Rafael; Cascales-Miñana, Borja ULiege; Santos, A. A. et al

Poster (2016, July)

Detailed reference viewed: 5 (0 ULiège)
Full Text
See detailChallenge testing with Brochothrix thermosphacta on minced pork meat shows interest to couple metagenetics to metabolomics to study food spoilage
Baré, Ghislain ULiege; Cauchie, Emilie ULiege; Leenders, Justine ULiege et al

Poster (2016, July)

The spoilage of perishable foods is mainly caused by bacterial activity. The risk of unwanted bacterial growth is particularly high in the minced pork meat. In this work, the natural microbial ... [more ▼]

The spoilage of perishable foods is mainly caused by bacterial activity. The risk of unwanted bacterial growth is particularly high in the minced pork meat. In this work, the natural microbial contaminants of the minced pork meat were followed by 16S ribosomal DNA deep sequencing (metagenetics) during aging tests at different temperatures. Brochothrix thermosphacta MM008 strain was selected as one of the main contaminants responsible for the spoilage of the meat. Minced pork meat previously sterilized by gamma irradiation was inoculated with B. thermosphacta MM008 for challenge tests measuring growth and then incubated at different temperatures. Minced meat samples were taken and analyzed by H-NMR 1D at time 0 and at final time (from 14 to 19 days, depending on the incubation temperature). Orthogonal partial least square discriminant analysis (OPLS-DA) showed that samples, regardless of the incubation temperature, could be splitted into 3 groups according to their spectral profile: 1) samples taken at time 0, 2) samples inoculated with B. thermosphacta and taken at final time, 3) samples uninoculated, taken at final time. From the analysis of the metabolomics data, higher concentrations of glycerol, glucose, taurine, lactate, carnitine, betaine and glycine were identified in the samples of uninoculated minced pork meat and an increased production of creatine, acetate and acetone was found in the samples of minced pork meat inoculated with B. thermosphacta MM008. These observations showed that -omics technologies (metagenetics and metabolomics) could be used conclusively to study microbial spoilage of minced pork meat. [less ▲]

Detailed reference viewed: 64 (13 ULiège)
Full Text
See detailInternal structures of clusters in driven granular gas
Noirhomme, Martial ULiege

Poster (2016, July)

Detailed reference viewed: 13 (4 ULiège)
Full Text
See detailContinuous monitoring of transient groundwater fluxes using the Finite Volume Point Dilution Method
Jamin, Pierre ULiege; Brouyère, Serge ULiege

Conference (2016, July)

Groundwater flux is the driving force of solute contaminant dispersion through aquifers. Accurate groundwater flux measurement and monitoring is thus crucial for assessing the fate of contaminants in the ... [more ▼]

Groundwater flux is the driving force of solute contaminant dispersion through aquifers. Accurate groundwater flux measurement and monitoring is thus crucial for assessing the fate of contaminants in the saturated zone. Unfortunately, classical measurement such as pumping or slug tests based on the Darcy’s law and hydraulic gradient may lead to cumulated errors and provide no more than a snapshot measurement only representative of a given time. There is a need for a technique able to perform a continuous monitoring of groundwater fluxes, and moreover in aquifer where rapid changes of groundwater fluxes occur such as aquifers influenced by surface water, by nearby pumping or by fast precipitation recharge. Alternative methods, such as point dilution tracer tests to obtain a direct measurement of local groundwater fluxes, are promising In this study, the Finite Volume Point Dilution Method (FVPDM) was applied to continuously monitor groundwater fluxes of the alluvial aquifer of the River Meuse, in Liège (Belgium). The experimental setup consisted in the monitoring of a transient groundwater fluxes generated by a step pumping test that lasted 40 hours. Two FVPDM were performed simultaneously in two piezometers screened in two different part of the aquifer. Piezometric heads were also monitored in several piezometer located around the pumping well. Next to this original experimental setup, a mathematical solution has been developed to interpret data from FVPDM performed under transient state in order to deduce the continuous evolution of groundwater flux. The experiment demonstrated the ability of the FVPDM for monitoring transient groundwater fluxes, even if the changes of groundwater flux occurs rapidly. The FVPDM turned out to be very sensitive to small changes in groundwater flux. The FVPDM interpretation also showed that the upper part of the aquifer is affected by slower groundwater fluxes than the lower and coarser part. Furthermore, distinct hydraulic behavior were determined between the upper and lower part of the aquifer. This could not have been revealed by conventional pumping tests using only drawdown data for interpretation. The mathematical solution allowed to determine the groundwater flux at every moment of the test even if the FVPDM had not reached the stabilized phase that usually guarantee its good precision. These results illustrate the great interest of the FVPDM method for monitoring of contaminant fluxes in groundwater if coupled with a real time measurement of contaminant concentration. One of the main perspective is to perform a long term (several months) monitoring of groundwater fluxes in an aquifer influenced by river stages variations in order to prove the ability of the FVPDM for continuous long term monitoring and better characterize the exchanges between groundwater and surface water. [less ▲]

Detailed reference viewed: 33 (12 ULiège)
Full Text
Peer Reviewed
See detailThe different origins of high- and low-ionization broad emission lines revealed by gravitational microlensing in the Einstein cross
Braibant, Lorraine ULiege; Hutsemekers, Damien ULiege; Sluse, Dominique ULiege et al

in Astronomy and Astrophysics (2016), 592

We investigate the kinematics and ionization structure of the broad emission line region of the gravitationally lensed quasar QSO2237+0305 (the Einstein cross) using differential microlensing in the high ... [more ▼]

We investigate the kinematics and ionization structure of the broad emission line region of the gravitationally lensed quasar QSO2237+0305 (the Einstein cross) using differential microlensing in the high- and low-ionization broad emission lines. We combine visible and near-infrared spectra of the four images of the lensed quasar and detect a large-amplitude microlensing effect distorting the high-ionization CIV and low-ionization Hα line profiles in image A. While microlensing only magnifies the red wing of the Balmer line, it symmetrically magnifies the wings of the CIV emission line. Given that the same microlensing pattern magnifies both the high- and low-ionization broad emission line regions, these dissimilar distortions of the line profiles suggest that the high- and low-ionization regions are governed by different kinematics. Since this quasar is likely viewed at intermediate inclination, we argue that the differential magnification of the blue and red wings of Hα favors a flattened, virialized, low-ionization region whereas the symmetric microlensing effect measured in CIV can be reproduced by an emission line formed in a polar wind, without the need of fine-tuned caustic configurations. [less ▲]

Detailed reference viewed: 19 (4 ULiège)
Full Text
See detailL'argumentation dans les écrits scientifiques : le point de vue des chercheurs
Scheepers, Caroline ULiege; Delneste, Stéphanie

in Pollet, Marie-Christine; Glorieux, Carole (Eds.) Argumenter dans les écrits scientifiques (2016)

La question de la conduite argumentative repérable dans les discours scientifiques suscite de nombreux débats, comme le montre cette liste non exhaustive : Charaudeau (1992, 2007), Amossy (2009), Cislaru ... [more ▼]

La question de la conduite argumentative repérable dans les discours scientifiques suscite de nombreux débats, comme le montre cette liste non exhaustive : Charaudeau (1992, 2007), Amossy (2009), Cislaru et al. (2009), Scheepers (2013), Pollet (2014)... Bon nombre d’études inscrites dans le champ des littéracies académiques consistent la plupart du temps à étudier des corpus de textes, inscrits dans des genres divers, dont les auteurs sont des étudiants, des chercheurs novices ou expérimentés. D’autres études explicitent et analysent les effets produits par un dispositif d’enseignement-apprentissage visant à acculturer les néophytes aux subtils rouages de l’écriture scientifique. Notre contribution repose sur un parti-pris méthodologique tout différent : le principe est d’interroger les chercheurs, confirmés ou non, issus des toutes les disciplines, à propos de leurs représentations ou de leurs pratiques s’agissant de l’argumentation à l’œuvre dans les travaux scientifiques. Ainsi, considèrent-ils qu’une recherche vise à démontrer une thèse ? Pensent-ils que le chercheur doit rester neutre et/ou objectif ? Estiment-ils que le chercheur soit tenu de contre-argumenter ? Quel degré d’argumentativité confèrent-ils aux différentes étapes de la recherche ? Comment décrivent-ils leurs propres pratiques argumentatives et celles de leurs étudiants ? Autant de questions, parmi d’autres, qui mettent en avant les tensions, les polémiques qui se font jour dans les études relevant des littéracies académiques. [less ▲]

Detailed reference viewed: 22 (0 ULiège)
Full Text
See detailMotiver sans contraindre, séduire sans manipuler
Defays, Jean-Marc ULiege

in Le Langage et l'Homme (2016), 2016-1

Detailed reference viewed: 40 (11 ULiège)
Full Text
Peer Reviewed
See detailThe role of biochemical of bone turnover markers in osteoporosis and metabolic bone disease: a consensus paper of the Belgian Bone Club.
Cavalier, Etienne ULiege; Bergmann, P.; Bruyère, Olivier ULiege et al

in Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA (2016), 27

The exact role of biochemical markers of bone turnover in the management of metabolic bone diseases remains a topic of controversy. In this consensus paper, the Belgian Bone Club aimed to provide a state ... [more ▼]

The exact role of biochemical markers of bone turnover in the management of metabolic bone diseases remains a topic of controversy. In this consensus paper, the Belgian Bone Club aimed to provide a state of the art on the use of these biomarkers in different clinical or physiological situations like in postmenopausal women, osteoporosis in men, in elderly patients, in patients suffering from bone metastasis, in patients with chronic renal failure, in pregnant or lactating women, in intensive care patients, and in diabetics. We also gave our considerations on the analytical issues linked to the use of these biomarkers, on potential new emerging biomarkers, and on the use of bone turnover biomarkers in the follow-up of patients treated with new drugs for osteoporosis. [less ▲]

Detailed reference viewed: 41 (7 ULiège)
Full Text
Peer Reviewed
See detailHeritage Conservation in River Corridor Cities. The Case of Tripoli, Lebanon.
Ginzarly, Manal ULiege; Teller, Jacques ULiege

Conference (2016, July)

This article recognizes rivers as cultural heritage landscapes, as an integral component of cities common heritage and an element of collective memory and identity. It is based on the consideration that ... [more ▼]

This article recognizes rivers as cultural heritage landscapes, as an integral component of cities common heritage and an element of collective memory and identity. It is based on the consideration that analysis of the socio-spatial relationship between the river and urban structure at different historical period can further lead to knowledge about the river contribution in forming the identity and sense of place of an urban area. This knowledge can be used to inform urban conservation as well as development practices to support the integral spatial and cultural relation between the city and the river in order to maintain the character of river city. This article takes the historic core in the city of Tripoli, Lebanon as a case study where conservation practices have followed a monument centric approach focusing on the restoration of heritage buildings and sites and neglecting the cultural value of the Abu Ali River flowing through the city. It conducts a multi- dimensional morphological analysis that is based on archival review and field work to extract the social value of the river and its contribution to the urban morphology of the city. [less ▲]

Detailed reference viewed: 83 (19 ULiège)
Full Text
See detailCOST Action FA1407: Empowering NGS technologie for study and diagnostic of plant viruses
Massart, Sébastien ULiege; Petter, François

Conference (2016, July)

Detailed reference viewed: 20 (1 ULiège)
Full Text
See detailBeIPD-COFUND satisfaction survey | Results
Delahaye, Raphaela ULiege

Report (2016)

This survey has been performed in December 2015 >January 2016 in order to measure the level of satisfaction of the applicants who, in 2013, 2014 or 2015, applied for an incoming or outgoing BeIPD-COFUND ... [more ▼]

This survey has been performed in December 2015 >January 2016 in order to measure the level of satisfaction of the applicants who, in 2013, 2014 or 2015, applied for an incoming or outgoing BeIPD-COFUND postdoctoral grant at the University of Liege. [less ▲]

Detailed reference viewed: 20 (7 ULiège)
Peer Reviewed
See detailSymposium. Quels leviers pour aider les élèves à résoudre des tâches complexes ?
Colognesi, Stéphane; Fagnant, Annick ULiege; Hanin, Vanessa et al

Conference (2016, July)

Detailed reference viewed: 53 (5 ULiège)
Peer Reviewed
See detail2D and 3D FE models of laser cladding process
Jardin, Ruben; Hoang, Son Tran; Hashemi, Seyedeh Neda ULiege et al

in Booklet of the conference with extended abstract and short paper of less than 6 pages (2016, July)

Lien entre le champ thermique 2D et 3D calculé pour un cas de laser cladding d acier au chrome

Detailed reference viewed: 49 (19 ULiège)
Peer Reviewed
See detailDe l’activation à la précarité : analyse de deux dispositifs d’intervention sociale
Gérard, Julie ULiege; Vrancken, Didier ULiege

Conference (2016, July)

La lutte contre le chômage de longue durée et l’exclusion sociale par un retour à l’emploi représentent des enjeux essentiels des politiques actives du marché du travail. C’est pourquoi, cette ... [more ▼]

La lutte contre le chômage de longue durée et l’exclusion sociale par un retour à l’emploi représentent des enjeux essentiels des politiques actives du marché du travail. C’est pourquoi, cette communication s’intéresse aux effets de l’intervention sociale sur les demandeurs d’emploi à partir de l’analyse de deux dispositifs d’activation situés en Belgique francophone : une Entreprise de Formation par le Travail et une agence de Titres-Services. Au moyen d’une étude qualitative reposant sur une soixantaine d’observations de situations d’interactions réalisée entre bénéficiaires et « travailleurs du social » (consultant, assistant social, formateur, etc.) et, d’une quarantaine d’entretiens semi-directifs, nous rendrons compte de l’action de ces deux dispositifs dans le domaine de l’insertion-socioprofessionnelle. Nous illustrerons combien, par l’articulation de politiques d’emploi à vocation universelle et de politiques particularistes destinées aux personnes les plus fragiles, ces dispositifs génèrent de véritables trappes à précarité. À terme, nous montrerons combien le maintien de ces dernières soulève la question du développement progressif d’un nouveau régime de protections, opérant a minima, voire par défaut, auprès des publics peu qualifiés face à la menace sourde que font peser le marché noir et, plus largement, l’informalité du travail. [less ▲]

Detailed reference viewed: 114 (17 ULiège)
Peer Reviewed
See detailClownfishes
Colleye, Orphal ULiege; Iwata, Eri; Parmentier, Eric ULiege

in Frederich, Bruno; Parmentier, Eric (Eds.) Biology of Damselfishes (2016)

Detailed reference viewed: 32 (5 ULiège)